Mixing devices for bone cement are known. One of such mixing devices is shown, for example, in applicant's German patent application DE 10 2007 041 666 A1.
When mixing bone cement, a powder, in particular an acrylate, is mixed with a liquid monomer. After mixing the components a crosslinking reaction occurs during which the bone cement progressively solidifies. The mixed, but not yet solidified bone cement is applied for example into medullary canals in which then a prosthesis is implanted. To prevent bubbles from being formed or to prevent harmful gases from being released into the environment, vacuum-mixing systems are known, in which a vacuum hose is attached to the mixing vessel.
A drawback of such known vacuum mixing systems is that a pump is required to generate the vacuum. Moreover, when mixing bone cement there are stringent requirements for sterility. A disadvantage of known mixing systems is that air enters into the mixing vessel already during mixing.
Also, in many cases known bone cement mixing systems are inconvenient to use, and due to the necessary variety of procedure steps for mixing there is a risk that the user makes a mistake, in particular that the ratio between the monomer and the bone cement powder is not correctly adjusted.